[PATCH] NFSD: pass range end to vfs_fsync_range() instead of count

[Brian Foster <bfoster@redhat.com>]

_nfsd_copy_file_range() calls vfs_fsync_range() with an offset and
count (bytes written), but the former wants the start and end bytes
of the range to sync. Fix it up.

Fixes: eac0b17a77fb ("NFSD add vfs_fsync after async copy is done")
Signed-off-by: Brian Foster <bfoster@redhat.com>
---

Hi all,

This is just a quick drive-by patch from scanning through various flush
callers for something unrelated. It looked like this instance passes a
count instead of the end offset and it was easy enough to throw up a
patch. Compile tested only, feel free to toss it if I've just missed
something, etc. etc.

Brian

 fs/nfsd/nfs4proc.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
index 8beb2bc4c328..3c67d4cb1eba 100644
--- a/fs/nfsd/nfs4proc.c
+++ b/fs/nfsd/nfs4proc.c
@@ -1644,6 +1644,7 @@ static ssize_t _nfsd_copy_file_range(struct nfsd4_copy *copy,
 	u64 src_pos = copy->cp_src_pos;
 	u64 dst_pos = copy->cp_dst_pos;
 	int status;
+	loff_t end;
 
 	/* See RFC 7862 p.67: */
 	if (bytes_total == 0)
@@ -1663,8 +1664,8 @@ static ssize_t _nfsd_copy_file_range(struct nfsd4_copy *copy,
 	/* for a non-zero asynchronous copy do a commit of data */
 	if (nfsd4_copy_is_async(copy) && copy->cp_res.wr_bytes_written > 0) {
 		since = READ_ONCE(dst->f_wb_err);
-		status = vfs_fsync_range(dst, copy->cp_dst_pos,
-					 copy->cp_res.wr_bytes_written, 0);
+		end = copy->cp_dst_pos + copy->cp_res.wr_bytes_written - 1;
+		status = vfs_fsync_range(dst, copy->cp_dst_pos, end, 0);
 		if (!status)
 			status = filemap_check_wb_err(dst->f_mapping, since);
 		if (!status)
-- 
2.37.3